The present invention relates to a method of making a storage tank assembly, such as a fuel tank. The method includes the step of molding a container body over a portion of a plastic fixture to lock the fixture into the container body. The tank also includes easily installed components which can be easily mounted within the plastic fixture.
Traditionally, the fixtures in a plastic container such as a fuel tank are mounted to a metal plate. The metal plate provides a flat surface for a gasket which is used to prevent leakage of fuel from the tank. For example, the fixtures may be sandwiched between a pair of metal plates. The plates are bolted together with a gasket disposed between the plates to prevent leakage between the fixture and fuel tank. This requires placing a metal plate and screws inside the tank and on the outside of the tank. If the fixtures, gasket and metal plate are not property aligned, leakage can occur around the screws and gasket.
Additionally, when plastic tanks expand due to pressure build-up within the tanks, they create a curved surface commonly called "crowning". Such crowning also affects the sealing ability of a gasket with respect to the tank. Fuel tanks which have undergone crowning provide poor sealing and fuel may leak out of the tank.
The prior art has not successfully addressed these problems. Thus, there has been a need for an improved plastic container assembly which provides improved high-pressure capacity using plastic fixtures without metal plates or gaskets. There has also been a need for an improved method of manufacturing these container assemblies.